In June 1995, Australia's population was 18.1 million, almost twice the size it was 40 years ago, and four times the size in 1910.

An understanding of the dynamics of population growth is fundamental to policy making. Changes in fertility, mortality and net migration affect the size, distribution and structure of a population; vital ingredients for planning the provision of goods and services, such as housing, education, health and transport facilities1.

Traditionally, concerns about Australia's population centred around the need for expansion. It was generally believed that the nation would be more secure and prosperous with a substantially increased population2. The immigration program after World War II was based on the belief that Australia was too thinly populated to ensure its security, or to optimise its economic development2. More recently however, there has been concern about global over-population and the impact of population growth on the environment3.

It was in this context that the House of Representatives standing committee for Long Term Strategies released the results of their inquiry into Australia's Population 'Carrying Capacity'4. The committee acknowledged the impact of population size and growth on a wide range of social, economic and environmental issues, and recommended that the government adopt an explicit population policy4.

Population growth

The crude birth rate is the number of births in a calendaryear per 1,000 of the population at 30 June. Prior to 1994, these rates were based on the mean population for the calendar year.

The crude death rate is the number of deaths in a calendaryear per 1,000 of the population at 30 June. Prior to 1994, these rates were based on the mean population for the calendar year.

The growth rate is the change in the population during the calendar year expressed as a proportion of the population at the beginning of the year.

The ABS produces several series of population projections based on different combinations of assumptions about mortality, fertility and migration. Most of the data presented here are from Series A of the 1993-2041 projections because the assumptions (medium fertility and low overseas migration) most closely reflect prevailing trends. Some comparisons with Series D (medium fertility and high net overseas migration) are also included.

For detailed information on the assumptions underlying the population projections, see Projections of the Populations of Australia, States and Territories, 1993 to 2041 (cat. no. 3222.0).

ACTUAL AND PROJECTED POPULATION

Source: Australian Demography; Australian Demographic Statistics (cat. no. 3102.0); Projections of the Populations of Australia, States and Territories 1993 to 2041: Series A (cat. no. 3222.0)

Australia's population grew from 3.8 million at the turn of the century to 18.1 million in June 1995. While the population has grown steadily this century, rates of growth have fluctuated from year to year. These fluctuations are largely the result of fluctuations in net overseas migration, the growth from natural increase having been comparatively steady. Migration to Australia is controlled by government policy, and net migration is influenced by the political, economic and social conditions which motivate people to migrate to and from Australia.

The main source of population growth since the turn of the century has been natural increase. 67% of the population growth between 1901 and 1994 can be attributed to natural increase, and the remainder to net overseas migration. Both birth and death rates have declined since the turn of the century, with birth rates falling faster than death rates. While death rates have declined steadily this century, birth rates have shown greater fluctuations from year to year.

The age-sex profile of a population, itself a legacy of past patterns of growth, influences natural increase through both fertility and mortality rates. For example, a population with a relatively young age profile can expect a large number of births even if most women have few children. This is because of the large number of women of childbearing age. Conversely, as the population ages, the number of deaths can be expected to increase because of the relatively large numbers of older people.

The steady growth of the population at the national level masks considerable variation at the regional, state and territory level. Some regions have experienced population decline. Each component of population growth, natural increase and net overseas migration shows variation at the regional level (see Population - State summary tables). However, the most significant factor in regional variation in growth rates is net internal migration(see Australian Social Trends 1995, Internal migration).

POPULATION AND COMPONENTS OF GROWTH

Average annual growth rate

Period/year(a)

Population at end of period

Natural increase

Net overseas migration

Population increase

'000

%

%

%

Up to 1900

3,765.3

. .

. .

. .

1901-13

4,893.7

1.8

0.6

2.3

1914-19

5,303.6

1.4

0.0

1.4

1920-29

6,436.2

1.5

0.7

2.1

1930-38

6,935.9

0.9

0.0

0.9

1939-45

7,430.2

0.9

0.1

1.0

1946-60

10,391.9

1.6

1.0

2.7

1961-70

12,663.5

1.3

0.9

2.1

1971-80

14,807.4

1.0

0.5

1.5

1981-90

17,169.8

0.9

0.7

1.6

1991

17,384.5

0.8

0.5

1.3

1992

17,573.2

0.8

0.3

1.1

1993

17,746.6

0.8

0.2

1.0

1994p

17,931.8

0.7

0.3

1.0

(a) At 31 December.

Source: Australian Demographic Trends (cat. no. 3102.0)

The early decades (1901-1945)From the turn of the century until World War I (1901-1913) the average annual growth rate was high at 2.3%. This was due to a high birth rate, and high net overseas migration in the latter part of the period.

In 1911, the year of Australia's first national census, Australia had a young population whose age-sex profile had been formed by a long period of high fertility and high mortality. Almost 12% of the population were under 5, and only 4% were aged 65 or over. The median age was 24 years.

During World War I, disruptions to civilian migration caused a decline in net migration. Growth from natural increase also declined steadily, from 1.8% in 1914 to 1.1% in 1919. This was due to a fall in the crude birth rate, and a rise in the crude death rate. Average annual population growth rates fell from 2.3% in the period 1901-13 to 1.4% in the period 1914-1919.

Growth rates recovered in the post-war period, despite a fall in the crude birth rate. Annual growth rates averaged 2.1% in the 1920s. The increase in growth rates during this period was associated with increasing levels of migration to Australia following World War I.

The economic collapse in 1929 and the depression during the 1930s led to a sharp decline in growth rates, falling to an average of 0.9% in the period 1930-1938. This decline in growth was associated with low levels of net migration, and a sharp decline in the crude birth rate. This fell to 16.4 per 1,000 population in 1934, the lowest rate recorded up to that point in the century. It did not fall to this level again until 1976. The rate of growth from natural increase fell to 0.7% in 1934 and 1935, the lowest rate recorded this century.

During World War II annual growth rates remained relatively low, averaging 1.0% for the period 1939-1945. While the crude birth rate increased during the war years and the population grew through natural increase, growth through net migration was low.

ACTUAL AND PROJECTED POPULATION

Source: Australian Demography; Australian Demographic Statistics (cat. no. 3102.0); Projections of the Populations of Australia, States and Territories 1993 to 2041: Series A (cat. no. 3222.0)

COMPONENTS OF POPULATION GROWTH

Source: Australian Demography; Australian Demographic Statistics (cat. no. 3101.0); Australian Demographic Trends (cat. no. 3102.0); Projections of the Populations of Australia, States and Territories 1993 to 2041: Series A (cat. no. 3222.0)

The post-war period (1946-1960)The post-war period from 1946-1960 saw high annual growth rates averaging 2.7% per year. Migration was an important component of this growth with the government actively encouraging migration to boost Australia's population. During this period net overseas migration added 1.2 million people to the population, many of them Europeans displaced by World War II. 43% of this increase occurred during the four years from 1949-1952.

Despite the high contribution of net migration, most of the growth during this period was due to natural increase, the well-documented 'baby boom'. This could more appropriately be termed a 'marriage boom'. A greater proportion of the population married and had children, and women were starting and completing their childbearing earlier2. The proportion of women aged 15 and over who had ever married increased from 64% in 1921 to 79% in 1961(see Australian Social Trends 1995, Trends in marriage and divorce). Despite individual women having fewer children, a large number of children were born during this period because an increasing proportion of women had children (see Trends in fertility).

CRUDE BIRTH AND DEATH RATES(a)

(a) Rates per 1,000 population.

Source: Australian Demography; Australian Demographic Statistics (cat. no. 3101.0); Australian Demographic Trends (cat. no. 3102.0); Projections of the Populations of Australia, States and Territories 1993 to 2041: Series A (cat. no. 3222.0)

The sixties and seventies (1961-1980)Population growth remained relatively high during the 1960s, averaging 2.1% per year. Rates of natural increase and net overseas migration eased back slightly from the high levels of the post-war period. Part of the decline in natural increase is attributed to the availability of oral contraception from 1961.

Growth rates fell sharply in the first half of the 1970s, from a peak of 2.1% in 1970 to 1.0% in 1975. The average annual growth rate for the 1970s was 1.5%. Levels of net migration declined as the economy slowed and employment opportunities contracted. During the same period there was a decline in fertility.

By the end of the 1970s fertility levels were even lower than those during the great depression, and were below replacement level (the fertility level required for a population to replace itself without immigration in the long-term). This decline was associated with social and economic developments, including higher levels of education and increasing numbers of women entering the labour force. Mortality rates were also falling, although at an insufficient pace to offset the fall in fertility, leading to a fall in growth due to natural increase from 1.2% in 1970 to 0.8% in 1980.

Recent developments (1981-1994)Australia's population increased from 15.1 million at the end of 1981 to 18.1 million in June 1995. Average annual growth rates declined in this period, falling from 1.7% in 1981 to 1.0% in 1994. Australia's average annual growth rate for the period 1990-95 of 1.2% was lower than the world average annual rate over this period (1.6%), but similar to the rates of a number of other countries such as the USA, New Zealand, China, Singapore and Thailand5.

The rate of growth due to natural increase continued to decline between 1981 and 1994, with fertility remaining below replacement level and death rates declining at almost all ages. The rate of growth due to net migration fluctuated considerably during this period, recording some of the lowest and highest rates since World War II.

In 1995 Australia's age-sex profile reflected a low fertility/low mortality population. 7% of the population were under 5, and 12% were 65 or over. The median age was 32 years.

AGE - SEX PROFILE OF AUSTRALIA'S POPULATION, 1995 (actual)

Source: Australian Demographic Statistics (cat. no. 3101.0); Projections of the Populations of Australia, States and Territories 1993 to 2041 Series A (cat. no. 3222.0)

AGE - SEX PROFILE OF AUSTRALIA'S POPULATION, 2041 (projected)

Source: Australian Demographic Statistics (cat. no. 3101.0); Projections of the Populations of Australia, States and Territories 1993 to 2041 Series A (cat. no. 3222.0)

Where to from here? In the latest population projections produced by the ABS, growth rates are projected to continue to decline for at least the next 50 years, largely the result of expected declines in natural increase. The decline in natural increase is a combination of an assumed fall in the birth rate and an increase in the death rate due to the ageing of the population. By 2041, the population growth rate under Series A assumptions (medium fertility and low overseas migration) is projected to be 0.3%. Under an alternative assumption of high net overseas migration (Series D), the growth rate is projected to be 0.5% in 2041.

The population is projected to increase from 17.9 million in 1994 to between 24.9 million (Series A assumptions) and 26.7 million (Series D assumptions) in 2041. Under Series A assumptions, migration is projected to overtake natural increase as the most significant component of growth around the year 2026. This contrasts with the pattern of growth in the twentieth century, when natural increase was overall, the most significant component of growth.

Although net migration is projected to take over from natural increase as the most significant component of growth next century, the population will continue to grow through natural increase for some time. Despite fertility being below replacement level, Australia's population is projected to grow through natural increase until at least 2041 because of the large numbers of women of childbearing age. This is an echo effect of the post war 'baby boom', as the grandchildren of the large number of people born in the 1950s and 60s have their children. Even if Australia has no future net overseas migration, the population would continue to grow until 2032, peaking at about 20.5 million people.

The age-sex profile of the population projected for 2041 reflects a long period of low fertility and low mortality. A prominent feature is the relatively large proportion of older people, particularly older women. Although the proportion of women aged 65 or more in the population is projected to increase from 6.7% in 1995 to 12.3% in 2041, women of all ages will have increased their share of the total population by only a small amount (from 50.2% in 1995 to 50.9% in 2041). The projected median age of the population in 2041 is 41 years.